There's no way of really avoiding such failures, other than the obvious things like "don't store it in a damp cellar" etc. It's old electronics, these things break. The CPC isn't particularly prone to failure any more than any old computer, however, there are much more unreliable 8-bit computers out there (looking at you C64 Breadbin!).
What people do: They remove the PCB from the computer, pack it with lots of protection in a box. Send a PM to me or someone else known to repair 8-bit computers and say, "Here Bryce, can you fix this for me" and then head off to the post office.
Bryce.